


Just a Moment

by InuShiek



Category: Transformers (Bay Movies)
Genre: M/M, NSFW, Size Difference, Slash, Sticky, like a HUGE size difference. i regret nothing.
Language: English
Status: Completed
Published: 2014-02-09
Updated: 2014-02-09
Packaged: 2018-01-11 17:05:37
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 684
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1175617
Author URL: https://archiveofourown.org/users/InuShiek/pseuds/InuShiek
Summary: <blockquote class="userstuff">
              <p>Grimlock propositions the Prime for an interface, but Optimus underestimates just how big the Dinobot is.</p>
            </blockquote>





	Just a Moment

**Author's Note:**

> I got [two](http://inushiek.tumblr.com/post/75810501630/i-have-never-wanted-fic-of-grimlock-fucking-the-living) [messages](http://inushiek.tumblr.com/post/75811345872/oh-god-can-you-imagine-optimus-would-just-be-like-his) on tumblr, and I couldn't stop myself.

He’d never thought, when the big mech propositioned him, that he would find himself in this particular position.

Well, there is always a fifty percent chance that you will use your spike or your valve, of course, but-

"Grimlock!" the Prime gasps, clutching at the massive hand that is holding him high above the floor.

"What?" the mech asks, his normally growl-like voice even rougher than usual. The Dinobot, holding Optimus Prime’s frame easily in one hand, thrusts deeper into that tight valve.

Optimus groans at the mix of uncomfortable stretching of his valve and pleasure sparking off from his spike being sandwiched between his own plating and Grimlock’s palm. “Give me a moment, Grimlock,” he pants, and his sensor net informs him that lubricant is beginning to slip down his thighs.

"Moment for what?"

A burst of static escapes the Prime when Grimlock thrusts a bit deeper. “A moment to adjust,” he answers quickly. “Just… Just slow down, Grimlock.”

"Not want to frag? Can stop if Optimus want."

"No!" he answers a little too quickly this time, and his faceplates heat up. Primus he could swear his entire torso is having to expand to make room for the Dinobot’s spike. "No, Grimlock, I don’t want to stop, I just need you to go slowly for a while. It has been….quite a long time since I’ve done this….and never quite to this degree." Optimus cranes his helm around to look back and up at Grimlock, and he can see the large mech thinking on his words.

When Grimlock’s processors catch the Prime’s meaning, he growls deep in his chassis and tightens his grip on the smaller mech possessively. “Slow,” he echoes, pulling his spike out a bit before carefully thrusting in deeper.

Vents roaring, Optimus braces himself on Grimlock’s wrist while he wills his valve to relax and expand. He can feel lubricant pooling beneath his spike as it is rubbed against the mech’s palm. “Grimlock!” Optimus groans loudly as he overloads, grinding his spike into the Dinobot’s palm as his valve spirals down so tightly around the massive spike that Grimlock is forced to stop moving for several long moments.

"Optimus..?"

"Don’t stop," the Prime replies, panting. Out of curiosity, one of his hands slips between his body and Grimlock’s hand, and he moans quietly when he can actually feel his frame bulging outward to accommodate the spike.

Needing no further encouragement, Grimlock forces his spike deeper into the Prime the moment his valve relaxes enough to allow it, and a muffled cry from the small mech makes the Dinobot growl possessively once more.

Optimus returns his hand to gripping onto Grimlock’s wrist in an attempt to keep himself grounded as the Dinobot manages to press even deeper into his valve. Having an overload has heated his array and made it more susceptible to stretching, and the Prime is not receiving any pain signals any longer as lubricant continues to drip down his thighs.

As Grimlock thrusts deeper into Optimus, he can feel the mech tensing and jerking in his hold as the Prime’s valve begins to tighten once again. Unsure if the Prime could be nearing overload again so soon, the Dinobot thinks it better to ask and be sure. “Optimus hurt?”

"No G-uhn-Grimlock," Optimus gasps, trying to force his frame to be still. "Your spike is just…rather jammed against a node."

Grimlock quickly realizes what Optimus means, and, with a grin, he gives a sharp thrust into the node, toppling the Prime into another overload. This time, however, the Dinobot doesn’t let a tightened valve stop him from thrusting into the Prime, prolonging the mech’s overload.

With a deep rumble, the Dinobot decides he likes the sight of Optimus overloading in his hand, and he vows to overload the Prime several more times before the floods the relatively tiny mech’s valve with his lubricant. Sure, the Prime may be sore later, but Grimlock has a feeling he’ll be back very soon. “Yeah… Soon,” he mutters aloud as he finally brings his plating flush with the trembling Prime’s aft.


End file.
